Monday, May 6, 2013


In the event of an extended unpleasantness that effects power distributions, the name of the game turns into energy storage and management.  Quite simply, energy is life.  Energy sterilizes things, cleans things, cooks food, even moves things.  Energy storage has historically been in the form of solids: think firewood, coal or peat.  Liquid storage, such as diesel fuel, gasoline or liquified natural gas (LNG) are products of the petroleum age and it's really difficult to beat the energy density they provide.  But batteries are the natural for electrical energy storage, especially if the electricity is generated by solar cells, wind or water turbines. 

I won't go too much into batteries, I've talked a lot about batteries in these pages.  This is more about some practicality of "care and feeding" of your batteries. 

There's about a half-dozen different chemistries for rechargeable storage batteries on the broad market.  The most economical batteries for energy storage are lead acid, but the lead plates make them the heaviest type of battery.  Lithium batteries, in different detailed chemistries, are lighter (the reason they are often preferred for electric cars), and can have excellent energy densities, but they're more expensive than lead acid batteries.  There are Lithium Ion, Lithium Phosphate, and Lithium Iron in common use.  A compromise in terms of expense, weight, and ease of use is Nickle-Metal Hydride (NiMH), and improvement over the older Nickle Cadmium (NiCad) batteries.

There are two big facts you need to be aware of.  All types of rechargeable batteries have a number of cycles that they will handle, and have less capacity the more cycles they go through.  In addition, all batteries will discharge themselves over time, so you will need to charge them on some sort of schedule even if life is idyllic and your AC power is there 100% of the time.  I read those two facts to say I should treat my batteries as close to ideally as I can; so they have as much life and capacity left as possible when I need it.

I said in my solar panel project that deep cycle, AGM (absorbed glass mat) type lead acid batteries seem to be the best storage battery for this use and I still think that (more info here).   If you get one of those, a charger like this Schumacher I picked up at Walmart for $50 is all you really need.
AGM deep cycle batteries are the same chemistry as car starting batteries, but the differences in construction and use leaves little in common.  For optimum life they shouldn't be charged with a simple car charger like this one.

But what if, like me, you have a hodgepodge of batteries?  Some NiMH, some NiCads, sealed lead acid (Gell Cells) and some Li-Ion?   For about 6 or 8 years, I've been using a smart charger that is no longer manufactured for this task.  Called the CH-777 Plus, made by Maha, I could stick pretty much any battery in the house on it, lead acid, Ni or Li chemistries.  A few weeks ago, I managed to blow it up while reviving the battery for my cordless drill.  After a bit of shopping, I ended up ordering a charger from Amazon, only that one was obsolete and out of stock, too.  I spoke with the guys who were the actual seller and ended up with this one.  It will charge any chemistry Lithium battery, NiMH, NiCad, and lead acid.  It is very programmable - to the point where you really can't use it without programming it. 

"Wait a minute, old man, did you just say 'reviving the battery for my cordless drill'?"  If you read about rechargeable batteries, you'll find references to most of them losing capacity if they sit around too much.  I find it to be the bane of cordless power tools.  Whenever I go to pick up my drill/screwdriver, the battery is dead.  A way to rejuvenate many older batteries is to discharge and then recharge them. One feature the TAZR charger has that I was looking for is the ability to do a calibrated discharge of the battery.  It allows you to program the current (up to 1 Amp) and discharge the battery to a known level.

This weekend, I had a 9 year old APC UPS tell me it needed new batteries.  When I pulled them out, one said it was fully charged and fully discharged at the same time.  Dead.  The second said it was charged but allowed me to discharge it (it was very slow - only at 0.2 or 0.3 A even though I programmed it for more).  After recharging it, it discharged at a constant 1 Amp with no trouble.  Discharging and recharging recovered a 7AH sealed lead acid battery.

Now how we get power into the charger to charge batteries if the grid is down is a bit involved, so a story for another day.


  1. Yep, I've brought more than few back from the dead.

  2. A few years ago, I put together a small solar set up for emergency lighting. Very small, as in (4) 15w panels stuck in windows. They're funneled into a standard 125ah trolling battery.
    With this little rig I can run multiple 12v LED trouble lights (220mw each) for area/task lighting all night.
    The best part is I corralled a small 12v battery charger for AAA thru D (& 9v), which allows me to charge my flashlight, cell phone, etc. batteries.
    Made life much easier during an 11 day outage in the NE ice storm in '08.

  3. I've got two 125 Watt panels, charge regulators, and two large Optima D31 "Yellow Top" deep-cycle batteries.

    I can pretty much keep all of my Amateur Radio equipment on-the-air indefinitely.

    For those things that require AC, I've got a 3kW inverter to use with the batteries.

  4. My 3.1 KW system is now in place, except for wiring the 12 - 260W panels into the Outback battery controller/Out back inverter box. 48v system with 24 - 2 volt DEKA industrial batteries (Low Maintenance, and I'll be installing a battery watering system to keep them up). Probably doing a solar DHW system in the next couple of months, too.

    Before those dollars lose all of their value. This stuff may be better than more silver bullion ;-)